Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 121748
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1148 AM CST Thu Jan 12 2017

.UPDATE...
Issued at 605 AM CST Thu Jan 12 2017

Please see the new 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Friday)
Issued at 432 AM CST Thu Jan 12 2017

A fast moving shortwave will move from Manitoba into northwest
Ontario today, bringing chances for snow which may overlap into
the Borderlands of northern Minnesota, mainly during the morning
and early afternoon. Have kept to flurries and a sliver of slight
chance POPs as low level dry air will keep much precipitation
from falling in our area. This shortwave will also drag a cold
front across the area, bringing a fresh shot of cold, cold air
into the area. This is going to keep highs mostly in the single
digits today. Tonight, temperatures are going to plummet after
dark. Clearing skies and winds gradually dropping off as the
surface ridge settles in overhead are going to allow for good
radiational cooling conditions overnight. Most guidance has
minimum temperatures in the -15 to -25 range, with MOS in the -15
to -30 range. Given the fresh snow cover and personal experience,
have gone a few degrees colder than that yet, especially in our
cold spots across far northern Minnesota. It seems like a slam
dunk for a wind chill advisory/warning combo for tonight depending
on location. Have held off for now as we have an advisory out
already this morning. Despite the very cold morning, expect highs
to get back up around zero once again Friday. With the ridge
overhead Friday should be relatively quiet with mostly sunny
conditions. There is some potential for LES over the south shore
late tonight/early Friday as winds turn northwesterly. However,
while the wind trajectory is good and temperatures are cold enough
aloft, it appears that there will be too much dry air to let the
convective bands get going with the shorter fetch distances on the
western end of the lake, and may instead form farther east. Clouds
are certainly possible though, and have some increased cloud cover
and slightly warmer min temperatures.

.LONG TERM...(Friday night through Wednesday)
Issued at 432 AM CST Thu Jan 12 2017

Look for several days of quieter weather followed by a chance of
wintry mixed precipitation early next week.

A quieter weather pattern will continue through Sunday night as
the upper level flow gradually shifts from northwesterly to quasi-
zonal and eventually southwesterly by early next week. A subtle
shortwave trough will move through the area Friday night and early
Saturday morning, which may bring a few snow showers to northwest
Wisconsin. Without much moisture to work with, we expect only a
few tenths of an inch of snow accumulation. Temperatures will
gradually trend warmer through the weekend and into next week.

Attention then shifts to a deepening longwave trough over the
western United States which is expected to move from near Baja
California into the Central Plains by Monday night. Deterministic
and ensemble members are in slightly better agreement this morning
bringing the upper low into the Upper Midwest late Monday night or
Tuesday. There is a chance of a wintry mix of snow, freezing rain,
or sleet over portions of northwest Wisconsin Monday night and
Tuesday, with snow possible farther east and north. Confidence is
not especially high this morning, but anyone with travel plans
early next week is encouraged to keep up with the forecast through
the weekend.

The upper trough will linger over the Plains and Midwest through
the end of the week with pockets of DCVA and weak shortwaves
rippling through the flow. It`s likely we`ll see another few
rounds of light snow after Tuesday, but the wide variety of model
solutions doesn`t allow for much confidence this morning.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1148 AM CST Thu Jan 12 2017

A strong Arctic front associated with an area of low pressure over
southwestern Ontario Canada will move across the region. A tight
pressure gradient along the backside of the front will bring very
gusty west to northwest winds. Gusts between 30 and 35 knots were
observed over eastern ND/western MN at time of TAF issuance, so
some gusts may be up to 35 knots this afternoon. Along with the
gusty winds will be some vsby reductions as blowing snow is a
concern this afternoon. Upstream obs are showing vsbys as low as
one-quarter of a mile from the blowing snow. Ceiling heights may
reduce to MVFR categories as well, but this is expected to be
isolated.

As the low pressure and frontal boundary moves off to the east,
winds should decrease overnight and skies look to clear. The
weakening winds and clearing skies will increase radiational
cooling, which will lead to a very cold night ahead. Wind chill
values should fall to as low as -40 degrees in some locations.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH   6 -21   2  -5 /  10   0   0  20
INL   1 -29   1  -5 /  30   0   0  10
BRD   6 -26   4  -4 /   0   0  10  10
HYR  10 -24   7  -3 /   0   0   0  20
ASX  10 -15   7   0 /   0   0   0  20

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Gale Warning until 10 PM CST this evening for LSZ140>143-146-147.

     Small Craft Advisory until 4 AM CST Friday for LSZ121-144-145-
     148.

&&

$$

UPDATE...Huyck
SHORT TERM...LE
LONG TERM...Huyck
AVIATION...JTS



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